CVE-2021-4033 in kimai2
Summary
by MITRE • 12/09/2021
kimai2 is vulnerable to Cross-Site Request Forgery (CSRF)
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Analysis
by VulDB Data Team • 12/15/2021
The CVE-2021-4033 vulnerability affects kimai2, an open-source time tracking application that has been identified as susceptible to Cross-Site Request Forgery attacks. This vulnerability represents a significant security risk within the application's authentication and authorization mechanisms, potentially allowing attackers to perform unauthorized actions on behalf of authenticated users. The flaw exists in the application's handling of web requests and user session management, creating an exploitable condition that could compromise the integrity and confidentiality of time tracking data.
The technical implementation of this CSRF vulnerability stems from the application's failure to properly validate and verify the origin of incoming HTTP requests. When users are authenticated within the kimai2 application, their session cookies are automatically included with subsequent requests, but the system does not adequately implement anti-CSRF tokens or origin validation checks. This allows an attacker to craft malicious web pages or email attachments that, when visited by an authenticated user, automatically submit requests to the kimai2 application without the user's knowledge or consent. The vulnerability specifically impacts the application's ability to distinguish between legitimate user-initiated requests and maliciously crafted requests that attempt to exploit the user's authenticated session.
The operational impact of this vulnerability extends beyond simple data manipulation, potentially allowing attackers to create, modify, or delete time entries, user accounts, and administrative configurations within the kimai2 system. An attacker could exploit this weakness to add unauthorized time entries for themselves or other users, manipulate billing data, or gain elevated privileges within the application. The consequences are particularly severe in enterprise environments where kimai2 is used for payroll processing, project management, and resource allocation, as unauthorized modifications to time tracking data could result in financial losses, compliance violations, and operational disruptions. The vulnerability also increases the risk of privilege escalation attacks that could lead to complete system compromise.
Mitigation strategies for CVE-2021-4033 should focus on implementing robust CSRF protection mechanisms within the kimai2 application. Organizations should immediately apply available patches or updates from the kimai2 development team that introduce proper anti-CSRF token generation and validation. The implementation should follow established security frameworks such as those recommended in the CWE-352 category, which specifically addresses Cross-Site Request Forgery vulnerabilities. Security measures should include the deployment of CSRF tokens for all state-changing operations, proper validation of the referer header, and implementation of SameSite cookie attributes to prevent cross-origin request forgery. Additionally, network-level protections such as web application firewalls should be configured to monitor for suspicious request patterns that could indicate CSRF attack attempts. The ATT&CK framework's T1566 technique for "Credential Access" emphasizes the importance of protecting against such attacks that leverage authenticated sessions to gain unauthorized access to system resources. Organizations should also conduct regular security assessments and penetration testing to ensure that CSRF protections remain effective against evolving attack vectors.